1. Field of Invention
This invention relates to a process for the utilization of ruminant animal methane emissions, specifically to a process that utilizes the methane contained within ruminant animal exhalation as a source of energy.
2. Prior Art
Methane emissions from ruminant animals account for about twenty percent of total global methane emissions, and atmospheric methane accounts for about twenty percent of planetary warming. In addition to the environmentally destructive effects of ruminant animal methane emissions, such emissions represent wasted energy, as up to thirteen percent of the food ruminant animals eat is lost as methane. Accordingly, there have been significant efforts in the past to reduce ruminant animal methane emissions.
Ruminant animal methane emissions originate in the four-stomach digestive tract common to all ruminant animals, which includes the rumen, a large forestomach connected to the four-stomach digestive tract. The rumen contains a host of digestive enzymes, fungi, bacterium, and protozoa, and the bulk of digestion, as well as methane production, takes place here. Not surprisingly, all prior efforts to reduce methane emissions in ruminant animals, which include dairy cows, cattle, sheep, goats, water buffalo, and camels, have focused on modifications associated with the rumen or digestive tract.
Past modification efforts have included: vaccines designed to limit methanogenic, or methane-producing, microorganisms in the rumen or digestive tract; feed reformulations designed to alter the chemical or microbial environment of the rumen or digestive tract to limit methane production; feed reformulations designed to decrease the amount of methane-producing foods entering the rumen or digestive tract; and selective breeding aimed at encouraging the reproductive success of ruminant animals which produce relatively low amounts of methane, presumably as a result of factors associated with the rumen or digestive tract.
While most of these prior efforts and inventions have had some success in reducing ruminant animal methane emissions, none has been shown to completely, or even significantly, eliminate ruminant animal methane production. Since limited success in reducing methane emissions concurrently limits the economic benefits of using methane-reducing vaccines, feed formulations, or selective breeding, ruminant animal owners have generally been averse or reluctant to employ these methods. Thus, as the ruminant animal population continues to grow in accord with ever-increasing worldwide demand and methane reduction efforts fail to reduce emissions in any significant way, ruminant animal methane emissions remain a major source of both environmental degradation and unutilized energy.
Prior to the applicant's discovery, no methods were known to reduce ruminant animal methane emissions by utilizing such methane as a source of energy in energy consumption systems maintained outside of the digestive tracts of ruminant animals. In the past, all methane reduction processes have focused on limiting ruminant animal methane production rather than reducing emissions through a system of methane utilization. Thus, it is an essential feature of the present invention that ruminant animal methane emissions are significantly reduced through the direct utilization of ruminant animal methane as a source of energy.
Methane-utilizing, or methanotrophic, microorganisms are well-known in the microbiology art for their capacity to grow using methane as a carbon and/or energy source. Methanotrophic microorganisms, specifically bacteria, have even been employed to reduce ruminant animal methane emissions by being placed directly in the rumen or digestive tract of ruminant animals and subsequently limiting production at its source. They have never, though, been employed in a microbiological growth-and-harvest system which concurrently reduces ruminant animal atmospheric methane emissions and provides a means for harvesting the product of microorganism growth (i.e. microorganism biomass).
In short, the connection between ruminant animal methane emissions and methanotrophic growth-and-harvest systems has never been made. At least three major factors have likely contributed to inhibiting such a connection. First, it is not a well-known fact that around ninety-five percent of ruminant animal methane emissions exit the digestive tracts of ruminant animals as exhalation, rather than as flatulence. (The specific physiological pathway of ruminant animal methane emissions is a relatively new discovery.) Most continue to regard such emissions as components of low-volume, diffuse flatulence. Second, it is not a well-known fact that certain ruminant animals produce enough methane to make methanotrophic microorganism growth and harvest systems economically feasible. Consequently, all past ruminant animal methane reduction efforts have focused on decreasing methane production, rather than instituting methane utilization systems. Third, ruminant animal methane capture and conveyance systems have never been employed, largely for the reasons listed above. For these, and probably more, reasons, the connection between ruminant animal exhalation methane emissions and methanotrophic microorganism growth and harvest systems has never occurred.
No previous methods were known to reduce ruminant animal methane emissions by using such methane as a source of energy. Consequently, ruminant animal atmospheric methane emissions remain a significant source of environmental degradation and wasted energy.
The present invention relates to a process for the utilization of ruminant animal exhalation methane as a novel source of energy.